A quarter century of power

In 1989 something remarkable happened. You might remember the fall of the despised Berlin Wall that separated Germany. Certainly that was a remarkable event in human history, but it wasn’t the only noteworthy occurrence that year. Not far away in Wels, Austria, something else happened that, for pilots, was also important.

In 1989, Rotax Aircraft Engines introduced its 912 engine. The Berlin Wall may be gone and thank goodness for that advancement of freedom. Yet another kind of freedom was born with the Austrian company’s introduction of the 912.

In 2014, the company plans a major fly-in to commemorate this history. Many, including myself, will travel long distances to be part of the celebration.

The Little Engine That Could

A well-known children’s story speaks to something small doing something big. That metaphor works for the Rotax 912 engine.

Consider: The common Lycoming O-233 produces 100 horsepower (at 2300 rpm; higher power is available at increased revolutions) using 233 cubic inches of cylinder displacement. Rotax’s 912 ULS makes the same horsepower using only one-third the displacement, 83 cubic inches. The physically smaller powerplant is one way Rotax reduced weight.

Compact size is not the only benefit. Lycoming lists its O-233 weight at 214 pounds, where the Rotax 912 weighs 140 pounds. Both engines add weight for mounts, exhausts, and other components needed to operate.

All this translates to the Rotax 912 having a power-to-weight ratio of 1.4 pounds per horsepower, while the O-233 has 1.8 to 2.1 pounds per horsepower. To further reduce dimensions, Rotax chose liquid cooling, which better modulates temperatures, but does add some weight.

The European manufacturer may not have foreseen the development of Light-Sport Aircraft 25 years ago, but the 9-series engines seems created for the category. Indeed, in today’s market, Rotax engines account for approximately 80% of the engines on LSA and light kit airplanes.

Rotax’s 9-series engine has been made available in various configurations from a 80 horsepower 912 UL (that can run on regular auto gas) to 100 horsepower to 115 horsepower from the turbo-charged Rotax 914.

The company’s latest is the 912 iS Sport (pictured), a computer-controlled, fuel-injected engine with significantly reduced emissions and improved fuel economy. With the powerplant in use for nearly two years, its fuel miserliness has proven even better than predicted; common cruise consumption is only four gallons per hour or lower.

This efficiency combined with the ability to use automobile fuel — high test for the 100-horsepower model — or avgas or any combination helps 912 iS offer a means of keeping the cost of flying within the budget of most pilots.

In recent years, Rotax has also matched the 2,000-hour TBO of competitive engines further containing maintenance cost. Users often report that they rarely need to add oil, only periodically changing it as described in Rotax manuals.

Despite these positive attributes, less knowledgeable observers still sometimes deride Rotax as “one of those snowmobile engines.” It is true that Rotax made a large number of powerplants for snowmobiles, as well as watercraft, but the 9-series has received primary attention as an aircraft powerplant with dual ignition and many other features associated with highly reliable aircraft engines. Some models are certified to Part 33 standards.

The company still makes one two-stroke model, the Rotax 582, outputting 65 horsepower, but has reduced its involvement with two stroke engines for aircraft. Even snowmobiles and watercraft now frequently use four stroke engines to reduce emissions.

Beside aircraft engines, Rotax manufactures engines for many other vehicles, among them for BMW products and unmanned aircraft. A large, modern facility in Wels employs 1,100 people, plus robotic machines. Distributors around the world are held to high standards and mechanics are offered extensive training in five levels. More than 120 service centers are available worldwide.

Flying Higher, Faster, Stronger

So in early June, hundreds of light plane enthusiasts and others will gather in the town of Wels where the Weisse Moewe airfield will play host to a large assembly of light aircraft all powered by Rotax engines. The setting will be ideal for evaluation flights.

Surrounded by snow-capped mountains rising to great heights above verdant valleys and picturesque villages, Austria is known for its scenic beauty. From the Weisse Moewe field, Rotax engineers and test pilots regularly put their engines through real-life tests.

To further celebrate the special occasion, Rotax invited enthusiasts of their three-wheeled motorcycle, Can-Am Spyder Roadster, to join pilots on the last day of the event.

Since 1973 Rotax has delivered more than 7 million engines to a wide range of vehicles. In the aviation sphere, Rotax is celebrating delivery of the 50,000th powerplant in the 9-series. Counting all engines produced for aircraft, Rotax has delivered more than 170,000. Complementing the Rotax Aircraft Engine line, BRP Powertrain also supplies such well known brands as Ski-Doo, Lynx, Sea-Doo, Evinrude, Johnson (outboard engines), and Can-Am (off-road vehicles and road motorcycles).